pit slope monitoring

When I started my career as a geotechnical engineer for a big size open pit metal mine, at that time I didn’t have any idea how we can manage the stability of slopes, how we can detect slope failures, how we can detect rock falls, and how we can save man-machineries before a slope failure occurred. But after a few months, I could able to know that already a lot of monitoring instruments were invented which can give us a clear idea about slope behavior. Not only the slope behavior but also those instruments can predict also before a slope collapse.